Joint



Nov 25, 1941.

J. J. BIRKHOFER 2,264,035

JOINT Original Filed Aug. 23, 1939 INVENTOR ATTORNEYS Patented Nov. 25,1941 JOINT I J ohnv J. Birkhofer, Union, N. J., assignor to The Kroydon.Company, Maplewood;.N-. J., a corporation of New Jersey Originalapplication August: 23. 1939; Serial No.

291,473.. Divided. and this. application March: 15, 1941, Serial No.383,517.:

Claims. (01. 2734s)- The present. invention relates to jointstruc tureand more particularly to means for and a method of. joining two partimplements such' as tennis rackets, golf clubs" or: the like having awooden part and metal part, which mustbe joined securely. Thisapplication is a division" of my co-pending" application Serial Number.291',4'73, filed August 23,1939;

In golf clubs, tennis rackets or other similar sports implementsembodying awooden head member carried by a shaft handle or the, like ofa different material such as" metal; the problem of, securely joiningthe head member is of prevailing importance. The joint must be secure toprevent separation of the partsduring use with consequent danger toplayers and spectators. The joint must besimple; effective and capableof being made quickly on a. mass. production basis. Furthermore; thejoint must be sightly without sacrifice ofstrength or efiiciency.Sightliness of the joint is a cardinal necessity forsuccessfulmerchandising because the purchasers of sporting. goods react'most favorably to goods having a trim, graceful appearance. The use of.the means, and. method herein described. result in a joint. which in noway detracts from the. appearance; of the. implement. Itis a principalobject of the. present invention to providea method and means forobtaining ajoint. meeting the. foregoing. requirements.

To the. accomplishment of the. foregoing and such other objects. as. mayhereinafter appear, this invention consists in they method, constructionand arrangement of parts hereinafter described and then sought to bedefined in the appended claims, reference being had to the accompanyingdrawing forming a part hereof and which shows, merely for the purposesof illustrative disclosure, preferred embodiments of the invention, itbeing expressly understood, however, that various changes may be made inpractice within the scope of the claims without digressing from theinventive idea.

In the accompanying drawing, in which similar reference charactersdenote corresponding parts:

Figure 1 is. a. fragmentary side. elevation of a golf club embodying thenovel joint structure of the invention;

Fig. 2 is an enlarged. vertical section illustrating the details of thejoint. structure;

Fig. 3 is an enlarged fragmentary section of a portion of the jointstructure shown in Fig. 2;

Fig. 4 isa fragmentary side. elevation partially in vertical: sectionillustrating: a modified form of joint structure embodying theinvention: as applied to a tennis racket; and.

Fig; 5 is a perspective View of a metallic sleeve embodied in themodified joint structure iliustratedin li'iga 4 but equally applicableto the; cif club-of Figs. 1 and r r p 7 Referring tov the drawingandfirst to Figsi l to 3 inclusive;, H1 denotes-a golf club: shaft ofmetal. This shaft. may be solid; or tubular as in the: embodiment shown.The lower end of the: shaft is flared to form the tapered socket ll.This socket in sectional elevation isfrustoconical in: shape and, in theembodiment shown, hasasmoothinner surface.

A wooden golf clubhead I5 is adapted tobe attached to the shaft- NJ. Tothis? end, the hosel it of said shaft has a reducedtenon. or tongueportion IT in the shape of a truncatedcone which is adapted. to projectintothe-socket H. The diametricaldimensionsrof the tenon portion aresuch as to providea-elearance A from the inner walls of the socket H. .Ashoulder l8-is defined between the base end of the tenon and thebody ofthe hosel; r a

A wire 2.8 of copper or. other suitable: metallic material is tightlywound around the conical surface of thetenon portion II. The wirewinding-is made sufiiciently tight tocause the wire tobite into thesurface of the-wooden tenon as at 21, so that when the ends 2 2 (oneonly shown). of said wire are'fixedor anchored in suitable manner to thewound body of. the wire at 2-3 asbysoldering or the like, therewil-l-be-no'danger or possibility of said-wound body slipping: off thetenoni. V The. wire. surfaced tenon is now dipped in: or otherwise.coatedwith a flux. Then molten uniting-.metal such as solder is appliedto the flux covered winding by dipping or otherwise. Likewise, first.flux and thenmolten uniting metal. are applied to-the inner face. of thesocket H. of the shaft, While the uniting metal retained. by the wire onthe tenon and by the inner socket face is still. in. molten. condition,the tenon. [9. is rammed or otherwise forced. into the socket so thatits bottom edge H" abuts the. shoulder 18;. Theuniting. metal carried bythe wire and that on. the. socket wall. thus are united. Uponcooling,.-f or. example by dipping the joined parts in cold water, theuniting metal hardens and securely fixes the wire wound tenon to thesocket wall; It. is to be. noted thatpthe bonding metal or solderpenetrates the interstices or surface; depressions between adjacentturns of the winding so that the winding is firmly secured to thesocket.

The joint thus obtained presents no unsightly external wrappings,collars, sleeves or the like. As can be seen in Fig. 1, the outersurface configuration at the open end ll of the socket matches bothdimensionally and in shape the outer surface of the head H5 at theshoulder |8. Also since the shoulder l8 on the hosel abuts the end ll ofthe socket. These factors thus give a continuous smooth external outlineto the hosel end of the shaft which merges with the body of the shaft. ar

The method just described is applicable for joining wooden and metalparts other than golf clubs, the requisite being .(1) that a socket beprovided on the metal part anda metal surface be provided on the tenonof the wooden part frame. The base 4| of the frame has a tenon 4 ortongue 42 of reduced diametershaped to.

frusto-conical form. A shoulder 43 is defined by the tenon and the base.7

The handle- 45 of the racket is of metal and like shaft may be tubularor solid. The upper end of this handle is provided with a flared socket46 shaped to frusto-conical form interiorly and adapted to receivethe'tenon 4|. r

A tubular metal sheath 50 also having frusto conical form and admeasuredto fit snugly about the surface'of the tenon 4| is provided. This sheathis provided with clinching members which serve to secure the sheath tothe wooden tenon. The sheath is forced over the tenon and then theclinching members are driven into the wooden body of the tenon asillustrated in Fig. 4.

In assembling the racket frame and handle, the sheathed-tenon 42 isdipped into or otherwise coated with a flux. Then a molten unitingmetal, such as solder, which adheres to the surface of the sheath isapplied to the sheath. Similarly, the inner surface of the socket 46 isdipned'or coated with flux and then with the molten un t ng metal.metal-on both parts is in molten condition, the sheathed tenon 42 isdriven or forced into the socket 46 until the upper edge of said socketabuts the shoulder 43. The joint is then cooled by. dipping in water orthe like to harden the unit ng metal. The, firm union of the sheath andsocket surfaces bythe uniting metal results in a very stronglyjoinedracket frame and handle which ,will not come apart during stressesinci- While the said uniting dentto play. It is to be noted 'thattheuniting metal or solder 30 penetrates the depressions in the surface ofthe sleeve formed by the. clinching members 5| when they are driven.into the wood of the tenon so that the sheath is very firmly secured tothe socket.

Thus the process, in either of its aspects, generally comprisesproviding a wooden member having a tongue or tenon and a metal memberhaving a socket into which said tenon is adapted to extend, applying ametal sheath or covering to the tenon and binding said sheath orcovering the head and the socket at their junction are so admeasured asto present a smooth, unbroken outline thereat. It will also be observedthat in both modifications the metallic covering 20 or 50 has in effecta broken outer surface provided with depressions into which the bondingmetal united with the smooth internal surface of the socket extends.

It will be observed, too, that in the latter modification, the extensionof the bonding metal into the depressions formed by the embedment of theclinching members 5| creates abutments of bonding metal which strengthenthe joint still further' by increasing its resistance to rotarystresses.

Modifications in structure and method are contemplated within the scopeof the claims. I do not wish, therefore, to be restricted to the exactdetails described.

I claim:

1. Means for effecting a permanent joint'between two partsat leastone ofwhich is of metal, said means comprising a socket on one part having asubstantially smooth inner surface. a reduced tenon on the other partextending into said socket and being so admeasured as to provide aclearance between its surface and said inner surface of said socket, ametallic covering envelopingsaid tenon, clinching members integral withsaid covering each of which is driven into and permanentlyembedded insaid tenon, and so embedded provide said covering with an externalsurface having depressions above each clinching member, said last namedsurface being so admeasured that'its undepressed portions extend intosaid clearance and into contact with said inner surface of saidsocketwhile its depressions are spaced from said inner surface of said socket,and metallic bonding material bonding the entire outer surface of saidcoveringlto said inner surface ,of said socket, said metallic bondingmaterial filling. substantially all those portions of said clearance notfilled by said metallic covering and extending into, the saiddepressions of said external surface of said cover- 2. In a device ofthe character describedhaving a wooden head and a metallic handle shaft,means for permanently joining said head and said shaft, said meanscomprising a flared openended socket integral with one end of saidshaft, a complementally shaped reduced tenon having a base and integralwith the said head, said tenon defining a shoulder ,on said head at saidbase, and said tenon being so admeasured as to provide a clearancebetween its surface and the inner surface of said socket, and saidsocket having an outer surface configuration and dimensions at its openend matching that of saidv head at said shoulder, a metallic coveringsurrounding said tenon, clinching members integral with said coveringeach of which is permanently embedded in said tenon leaving depressionsin the outer surface of said covering over said clinching members, saidcovering being so admeasured that portions of said outer surface extendinto said clearance, said covering being bonded to said inner surface ofsaid socket by hardened bonding material, said bonding material fillingportions of said clearance not filled by said covering, and the edge ofthe open end of said socket abutting said shoulder whereby a continuoussmooth ex-' ternal outline at said joint is effected.

3. In a device of the character described having a wooden part and ametallic part, means for permanently joining said wooden part to saidmetallic part, said means comprising a flared, open-ended socket on saidmetal part, a tapered tenon on said wooden part extending into saidsocket and being so admeasured as to provide a clearance between itssurface and the inner surface of said socket, a tapered tubular metalsheath fitting over said tenon, clinching members integral with saidsheath driven into and embedded in said tenon, and so embedded providingthe outer surface of said sheath with depressions over said clinchingmembers, said sheath being so admeasured that it extends into saidclearance, and metallic bonding material bonding said sheath to theinner surface of said socket, said bonding material filling all portionsof said clearance not filled by said sheath and extending into saiddepressions.

4. In a device of the character described having a wooden head and ametallic shaft, means for effecting a permanent joint between said headand said shaft, said means comprising a socket on said shaft, a tenon onsaid head extending into said socket and being so admeasured. as toprovide a clearance between its surface and the inner surface of saidsocket, a metallic sheath surrounding said tenon, clinching membersintegral with said sheath driven into and embedded in said tenon and soembedded providing the outer surface of said sheath with depressionsover the said members, said sheath being so admeasured that it extendsinto said clearance, said sheath being bonded permanently to said innersurface of said socket by metallic bonding material, and said bondingmaterial filling all portions of said clearance not filled by saidsheath and extending into said depressions.

5. In a device of the character described having a wooden head and ametallic handle shaft, means for permanently joining said head and saidshaft, said means comprising a flared openended socket integral with oneend of said shaft, a complementally shaped tenon having a base integralwith said head, said tenon defining a shoulder at said base and being soadmeasured as to provide a clearance between its surface and the innersurface of said socket, and said socket having an outer surfaceconfiguration and dimensions at its open end matching that of said headat said shoulder, a metallic sheath fitting snugly about the surface ofsaid tenon and clinching members integral with said sheath and driveninto said tenon leaving'depressions in the outer surface of said sheath,said sheath being so admeasured as to extend into said clearance, saidsheath being bonded to the inner surface of said socket by hardenedbonding material, said bonding material filling all portions of saidclearance not filled by said covering and extending into saiddepressions, and the edge of the open end of said socket abutting saidshoulder whereby a continuous smooth external outline at said joint iseffected.

JOHN J. BIRKHOFER.

